A.10   TRANSMISSION POWERS AND PROTECTION RATIO

The power radiated by each satellite is defined in Table B 2 for various angles from the

boresight of the transmitting antenna.  The power flux density at the earth s surface for

satellites at greater than 5 degrees elevation submitted to the ITU, Ref 4 are as follows:

 152 dBW/m

2

 per 4 KHz   for C/A code signals in L1 band

 162 dBW/m

2

 per 4 KHz   for P code signals in L1 band

 168 dBW/m

2

 per 4 KHz   for P code signals in L2 band

The power output from a 0 dBic antenna is specified as :

 160 dBW for C/A and P code L1. 

 166 dBW for P code L2.

However, measurements of the signal strength suggest that the L1 GLONASS C/A

code is 2 to 3 dB stronger than GPS.  The Russians have defined a protection ratio

(wanted signal power to maximum tolerable interference) for the GLONASS signals as:

 15 dB for C/A code in L1 band

 25 dB for P code L1 and L2 bands.

GLONASS specify that a satellite in an adjacent frequency allocation shall not create

interference above  48 dB if visible. 

Table A 2.  GLONASS Transmitted Power

e, degrees

0

15

19

Notes

EIRP, dBW

25

27

23

For narrow and wide

band signals in L1

band

EIRP, dBW

19

21

18

For wide band signals

in L2 band

A.11   INFORMATION TRANSMISSION, BANDWIDTH AND CODE RATES

Each satellite transmits a navigation signal in the L1 band that includes two pseudo

noise signals, modulated by Biphase Shift Keying onto the carrier separated by a 90

deg phase shift.  The chip rate  of the pseudo random sequences are 0.511 MHz (C/A 

code) and 5.11 MHz P code.  Each satellite also  transmits the P code at 5.11 MHz on

the L2 frequency.  The Russians have stated the  P code is not included in the civil

system offered for general use.

A 11